Oh, the tutorial is spectacular. You certainly have a talent to explain the concepts. :)
Probably the only thing that also should be mentioned is a double buffering, which is a standard in 2D/3D graphics. It increases the smoothness of animation and reduces the flickering of the screen, allowing to switch vertical synchronization off with minimal detriment to userâ€™s experience.
If somebody is interested to know more about WGL_EXT_swap_control extension, here is a link to official description:
http://www.opengl.org/registry/specs/EX ... ontrol.txt
In particular it gives more detailed explanation of the parameter to BOOL wglSwapIntervalEXT(int interval)
The parameter <interval> specifies the minimum number of video frames that are displayed before a buffer swap will occur...
In addition to all that, it is rumored that you cannot disable V-Sync if it is prohibited in the options of video-driver.